The present invention is directed toward a weight stack for an exercise machine and more particularly toward a weight stack which is intended to be self-supporting and does not require additional equipment or a wall or the like for supporting the same in a vertical orientation.
Conventional weight stacks are normally comprised of a stack of brick-like weights vertically arranged on top of each other with a pair of vertically extending guide rods extending through the weights. The top of the weight stack is linked to a cable and pulley system which connects the stack to various exercise devices or stations. Each weight normally has an opening accessible to the user and a pull pin is inserted into a selected opening to determine how many weights in the stack are to be lifted along the guide rods when a user performs an exercise.
The design of most weight stacks for exercise machines includes the cable extending over the upper pulley extending from the same at an angle away from the weight stack. Accordingly, when a force is applied to the free end of the cable such as may be necessary to utilize the weight stack for performing an exercise, a horizontal force is applied to the top of the guide rods forming part of the weight stack. In order to prevent the same from tipping, the weight stack must, therefore, either be attached to a wall or must include some additional supporting members for preventing the same from tipping.
With respect to most multi-station exercise machines currently on the market, the foregoing is not a significant problem since there are normally numerous support rods and structures that make up the multi-station exercise equipment. Some of these can be used to help support the weight stack and prevent the same from tilting.
There may, however, be instances where a weight stack is needed and where there is no other structural support available for preventing the stack from tipping. This could be accomplished utilizing a conventional weight stack by simply having the free end of the cable extend straight vertically downwardly so that the force on the pulley and the guide rods is vertically downward. The free end of the cable can then extend around additional pulleys mounted at the floor level to then be connected to an exercise device.
This, however, creates the additional problem of requiring an additional support structure at the top of the weight stack that would have to extend away from the weight stack thereby increasing the space taken up by the weight stack. In addition, unless additional housings or enclosures are utilized, the freely moving cable would be exposed thereby possibly creating a risk of injury.
The present invention is designed to overcome the deficiencies of the prior art discussed above by utilizing one of the guide rods as the return for the cable. According to the invention, a weight stack apparatus for an exercising machine includes a weight stack comprised of a plurality of weights vertically arranged on top of each other with each of said weights including a pair of spaced apart substantially vertical apertures extending therethrough. A pair of spaced apart substantially vertically extending guide rods pass through the weights as they are moved up and down. At least one of the guide rods is hollow. An upper pulley is mounted adjacent the upper end of the hollow guide rod and a cable passes over the upper pulley. A first end of the cable extends downwardly toward the weight stack and includes means for selectively connecting any desired number of the weights to the first end of the cable. A second end of the cable extends downwardly through the hollow guide rod and around a lower pulley mounted adjacent the lower end of the hollow guide rod and is connected to the exercising machine.